Wah lau eh, white fillings are expensive.
The composite
ones cost a bomb already, I know from experience.
White fillings are slightly paler than your teeth color, but
eventually wear down to match your teeth color faster than you
think. I don't honestly trust teeth whitening products no matter
how safe they claim to be, coz of their corrosive nature. If you
want to whiten your teeth temporarily, still prefer to visit the
dentist to do it for a small fee.